In Vitro Evaluation of Antibodies

As we know, a complete monoclonal antibody includes an antigen-binding fragment (Fab) and a fragment crystallizable region (Fc). The Fab can bind to a tumor-associated antigen, while the Fc plays an important role in metabolic pathways, as well as in IgG cellular functions.

The molecular sequence and subtype of antibodies will affect the effector functions. Such effector functions include the antibody dependent cellular cytotoxicity (ADCC) triggered by Fc binding to the FcγRIII receptor (CD16A) of NK. The Fc can also bind with serum complement molecules (C1q) to form a membrane attack complex (MAC) that triggers complement-dependent cytotoxicity (CDC). When the Fc binds with macrophage receptors—namely FcγRIII (CD16A), FcγRII (CD32A) and FcγRI (CD64)—the antibody-dependent cellular phagocytosis (ADCP) is triggered.